The anxiety and suspense involved in staring as you see a friend is typing an instant message or facebook chat message but never seems to complete it. The feeling can last for minutes or even hours. Unfortunately unlike actual blue balls, chat blue balls can not be relieved by jerking off.

Person 1: "What's with Freddy, he was supposed to come out with us an hour ago?"
Person 2: "He looked pretty pissed, he's probably suffering from chat blue balls again."